Dual throttle control



1952 c. 0. STEWART DUAL THROTTLE CONTROL 2 SHEETSSHEET 1 Filed Dec. 7,1948 INVENTOR.

. CHARLES D. STEWART Agent C. D. STEWART DUAL THROTTLE CONTROL Oct. 14,1952 2 SHEETS-SHEET 2 Filed Dec. 7, 1948 IN VEN'I'OR. CHAR LES D.STEWART Age nt Patented Oct. 14, 1952 DUAL THROTTLE CONTROL Charles D.Stewart, Glendale, Calif., assignor to Lockheed Aircraft Corporation,Burbank, Calif.

Application December 7, 1948, Serial No. 63,988

This invention relates to an improved throttle control providing for thenormal operation of two powerplants as a unit from a single mastercontrol lever, with provisions for close adjustment of synchronism, andoverriding individual controls operable at the will of the pilot.

In multi-engined aircraft it has heretofore been the practice to provideindividual throttle levers positioned side by side for simultaneous orindividual operation by one hand of the pilot, the powerplants beingsubstantially synchronized by minor independent movements thereof and/orthereafter accurately synchronized by speed responsive devices driven bythe separate powerplants. Any of the powerplants could be separatelyshut down or operated, as in the case it was desired to assist in groundmaneuvering. In twin engined single pilot aircraft, on the other hand,it is desirable to add other controls to the throttle lever, which wouldnot be practical with separate levers, so that it has been necessary forthe pilot to shift his hand from the throttles to adjacent separatecontrols for such auxiliary functions which ideally should be operablesimultaneously with the throttle.

It is accordingly an object of this invention to provide a single masterthrottle lever or handle control having provisions for simultaneous andoverriding individual adjustments or operation of the throttle orcontrol levers for separate powerplants. The control lever forconventional type piston engines is commonly called the throttle as itoperates a valve in the intake duct thereof. For convenience in whatfollows I am using the term throttle to also refer to the control leverof jet or propeller drive turbine powerplants where such levers controlthe fuel supply and when moved past the idle position cut off the fuelsupply to stop such engines. While the embodiment hereinafter disclosedis primarily designed for the control of such turbine powerplants, it isequally suitable for use in controlling piston type engines. Such amaster throttle control permits the addition of auxiliary controls tothe hand grip thereof, which grip may carry switches and may belongitudinally and/or rotatably movable to control still other functionsinterrelated to the throttle control of the powerplant.

It is a further object of this invention to provide a master throttlecontrol lever normally used to simultaneously operate individual slavethrottle levers, which levers are disengageable from the master controlfor individual operation at the will of the pilot. A further refinementof this object is to provide a differential control for 3 Claims. (Cl.74-471) adjusting the position of the slave throttle levers relativeto'the master control lever whereby to enable close synchronization ofthe separate powerplants at an point in their range of operation.

It is also an object of this invention to provide a master throttlecontrol of the type described incorporating an adjustable and releasableidling position stop, the release of which stop can be accomplished by apredetermined movement of the pilots throttle hand without necessitatinga release of the flying controls by the pilots other hand. I It is alsoan object of this invention to provide a master and slave throttlecontrol lever arrangement of the type described wherein the individuallevers are subjected to an adjustable braking force adequate to maintainany relative adjustment of an individual lever unaffected by movementsof the other levers.

Other and further objects and advantages of my invention will appear asthe description of a selected embodiment thereof proceeds, and myinvention is not limited to the specific device to be now described.

In the drawings:

Figure 1 is a perspective View, partly broken away for clearness, of amaster and slave throttle lever arrangement embodying a specific form ofmy invention;

Figure 2 is a side elevation of the device of Figure l, with partsomitted for clearness;

Figure 3. is a central vertical section on the line 3-3 of Figure 4,showing details of the synchronizing adjustment;

Figure 4 is a fragmentary view from the left of Figure 2 showingthesynchmnizing adjustment mechanism to an enlarged scale; and

Figure 5 is a section on the line 5-5 of Figure 3. 1

As shown on the drawings, the throttle control of this invention isintended to be built into a side shelf ill in the cockpit ll of anairplane (not shown), and is intended to operate individual powerplantcontrol rods l2 and I3 which extend to the powerplants themselves. Inthe case of piston type engines these rods would operate throttle valvesfor fuel injection controls, and in the case of turbine powerplantswould operate fuel injection controls. For convenience, I willhereinafter refer to these controls as throttle controls. 7

In Figure 1 the throttle levers to be later described are pivoted on astationary shaft l4 mounted by means of a flange I5 on the wall of riedby the upper ends of the slave levers. These I levers I6 and H areconnected at their lower ends to the rods l2 and I3. As shown in Figurel, clockwise movements of the levers I6, I! and I8 tend to open thethrottles of the powerplants, and counterclockwise motion of theselevers closes the throttles.

Interposed between the slave lever l6 and the flange |5 is a stationarybrakeelement 2| anchored to fixed structure at 22. This element 2| has apin 23 which holds stationary a pair of discs 24 on either side of thelever IS. A second identical element 2| similarly holds stationary asecond pair of the discs 24, located on either side of the other slavelever ll. Adjustable braking pressure is put on this assemblage by a hub25 of a hand wheel 28 which hub is threaded on the shaft M and may betightened as desired by the pilot to give sufficient friction for smoothoperation of the levers and/or to hold them in their adjusted positionif it is desired to take the hand off the master lever. The provision ofstationary discs 24 between each of the movable parts assures that ifeither slave lever H5 or I1 is disconnected from the master lever itwill remain in its set position, unaffected by subsequent movements ofthe master lever.

As described so far, the normal operation of the master lever carriesboth slave levers with it and the pilot merely has to grasp and push orpull on a knob 21 carried by the upper end of the master lever l8, whichknob also may be rotatable and/or slidable on the lever |8 to actuateother accessory controls unrelated to the present disclosure. If it isdesired to idle or shut down one powerplant, its slave lever I6 or I! ispulled sideways to disconnect it from the pin IE] on the master lever,and the slave lever would then be moved counterclockwise. As shown inFigure 2, the slave lever H has been moved clockwise to open itsthrottle, a less likely but possible procedure, so shown for conveniencein the drawing layout. Thereafter, control of the other powerplant wouldcontinue to be through the master lever.

The lever l8 carries an angularly disposed arm 28 at its lower end whichforms an idling stop against the lower end of an adjustable screw 29mounted in a pivoted nut bracket 30 and having a head 3| projectingthrough a slot in the shelf ID. A spring 32 normally holds the screw 29vertical in a position to intercept the end of the arm 28, thus definingthe idling position. A light spring 33, on top of the arm 28 facilitatesthe release of the idling stop when it is desired to move the masterlever |8 beyond that stop to shut down the powerplant. This spring 33 isadapted to be depressed upon pressure of the arm 28 towards the idlestop 29 and the brake knob 26 can be set tight enough to hold the lever=|8 in such position, so that the pilot can momentarily shift histhrottle hand from the grip 21 to pull the knob 3| shifting the idlestop 29 off the spring 33 and clear of the end of the arm 28, in

4 which position the spring 33 will move up to hold the idle stop in itsreleased position to permit a return of the pilots hand to the grip 21to continue the counterclockwise movement of the throttle lever past itsidle position to shut down the powerplants.

The pins [9, which normally look the slave levers l6 and I! for movementwith the master lever I8, form, in effect, diametrically opposed crankpins projecting from crank discs 34 flush with the sides of a member 35carried by the master lever l8. The member 35 is conveniently split onits center line and serves to support the discs 34 and a central wormgear 36 therebetween, the worm gear being adjustable by means of a worm31 operated by an external knob 38. In the neutral position the pin |9on one side disc 34 will be at its top position and the pin IS on theother disc will be at its bottom position. Rotation of the knob 33 ineither direction will move one pin and its associated slave lever in adirection to slightly open its throttle and simultaneously moves theother pin and its associated slave lever in a direction to slightlyclose its throttle. Thus the two powerplants can be closely synchronizedin any position of the master lever, yet either slave lever can bepulled sidewise off its pin l9 and moved independently of the masterlever to either open or close the throttle controlled thereby, leavingthe master lever free to continue to operate the other slave lever if sodesired. A stop 39, carried by the member 35, is adapted to cooperatewith a cut-away part of one disc 34 to limit the range of movementthereof as best shown in Figure 2.

It will thus be seen that I have invented an improved and simplifiedthrottle control for dual powerplants wherein either powerplant can beseparately operated at will and wherein close synchronization of theseparate throttles can be attained without the use of complicated powerdriven synchronizing apparatus.

I claim:.

1. A throttle control arranged to permit both simultaneous and separatecontrol of separate power plants comprising a pivoted master controllever, pivoted slave control levers disposed on either side of saidmaster lever, and operable independently thereof a shaft on which saidmaster and slave levers pivot, said shaft having a flange on one endstationary friction members disposed on both sides of each slave lever,and adjustable handwheel threaded on the free end of said shaft andarranged to compress said friction members and levers together to varythe frictional resistance of said levers to pivotal movement, and meansreleasably engaging each of said slave levers to said master lever forthe operation of either or both of said slave levers by said masterlever.

2. A throttle control arranged to permit both simultaneous and separatecontrol of separate power plants comprising a pivoted master controllever, pivoted slave control levers disposed on either side of saidmaster lever, a shaft onwhich said master and slave levers pivot,stationary friction members disposed on both sides of each slave lever,adjustable means carried on said shaft and arranged to compress saidfriction members and levers together to vary the frictional resistanceof said levers to pivotal movement, means releasably engaging each ofsaid slave levers to said master lever for the operation of either orboth of said slave levers by said master lever, and means todifferentially adjust the position of said slave levers relative to themaster lever when said slave levers are engaged to said master lever.

3. A throttle control arranged to permit both simultaneous and separatecontrol of separate power plants comprising a pivoted master controllever, pivoted slave control levers disposed on either side of saidmaster lever, a shaft on which said master and slave levers pivot,stationary friction members disposed on both sides of each slave lever,adjustable means carried on said shaft and arranged to compress saidfriction members and levers together to vary the frictional resistanceof said levers to pivotal movement, means carried by the master leverand located between said slave levers comprising a transverse shafthaving eccentric pins oppositely disposed and each engageable with oneof said slave levers, and means to rotate said shaft to differentiallyadjust said slave levers relative to the master lever.

CHARLES D. STEWART.

6 REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number

